Process for preventing the deposition of dispersed substances in dispersions



Patented Dec. 23, 1%41 I UNITED STATES, PATIENT. OFFICES PROCESS FOR PREVENTING THE DEPOSI- TION OF DISPERSED SUBSTANCES IN DIS- PERSIONS Paul Kiimmel,. Oranienburg, near Berlin Germany 3 Claims. (01.106-287) (Granted under the provisions of sec. 14, act of March'2, 1927; 357 0. G. 5)

This invention relates to a process for prethe like characterised by the feature that to venting the deposition of dispersed substances the constituents of the paint, for example bindin dispersions, for example in-paints containing ing agent, pigment and blending agent is added solid particles in suspension of which the more at least one watersoluble soap .of a nitrogenous: important are oil and varnish paints. Such 5 base, in particular an amine base.

paints generally comprise bindingagents in the The method according to the invention may form of a solution having a base of an oil, be carried out as follows: To the oil and varnish varnish,- or natural or artificial resin in -which binding agents and solutions containing pigwhite, coloured or non-coloured pigments, or ments or separating agents; are added, preferblending agents are dispersed. The most imably as soon as possiblgeiaiter the addition of portant agents consists of or contain drying oils, the substance to be dispersed, a sufficient quanfor example linseed oil, resin oil and the like. tity-generally 0.1 to 0.2%-of a water-soluble Important varnishes are also obtained from a fatty aminebase, which if desired may contain base of resin, or a modified resin of the glycerine one,or more free hydroxyl groups in the molephthalic acid series, the glycerine maleic acid cule. The fatty acids are all those which form series or the like. Of equal importance are soaps, for example dodecylic, tetradecylic, hexapaints wherein the binding agent contains celdecylic, octadecylic, octadecenylic, naphthenic, lulose ether or ester or condensation resins and resinic, ricinoleic or marine fatty acids. As

polymerisation resins other than the abovebases, use may be made of ammonia, or ethanol mentioned kinds. Q amine, di-ethanolamine, tri-ethanolamine, as

In such binding agents there is dispersed for well as mixtures thereof, hydrogenated diphenylthe formation of oil or varnish paints, coloured amine, ethylendiamine, di-ethylentriamine, trior non-coloured pigment with or without the ethylentetramine and the like as well as mix addition of blending agents. The substances tures thereof or mixed with ammonium soaps. added may for example be barium sulphate, The nitrogenous soaps may be added any time mica, talcum and the like, i. e. substances which after mixing the paint base with the binding do not themselves dissolve but remain floating agent, but it is preferable to add it soon after in a fine condition, and a solvent such as benzine the addition of pigment. In any case the addimay also be added. The suspended particles tion should be effected before the formation of are inclined after a shorter or longer time to the above-mentioned cement-like deposit albecome deposited, i. e. the duration of the susthough it is to be noted that even after this has pension is generally limited and the deposited been formed the addition of the soaps can enparticles have the inconvenient property of adable the deposit to be again brought into sushering together to form a mass of cement-like pension although in this case a considerable hardness, which cannot be loosened and brought amount of energy is required.

into suspension again in any manner. In the presence oi a small quantity of water" It has already been proposed to overcome this the effect may be considerably increased. It is disadvantage by the use of soaps of the alkali to be noted that water is formed in the formaearth metals, magnesium, aluminium and other tion of soap but an addition of water in excess metals, which soaps are insoluble in water but thereof is advantageous. not in benzene and similar organic solvents, but Finally, the addition of a resin or a saponifled in practice this method does not always produce resin, for example coumarone resin or rosin and the desired results and if relied upon absolutely their saponification products, is of advantage. will, in the cases where it is ineffective involve The invention is illustrated by the following damage to and loss of considerable quantities of example but is not limited to the particular depaint. Furthermore, in many cases the adhetails given therein.- sive or matting effect of earth alkali and metal 10 parts by weight of ethylendiaminoleate is very prejudicial. (formed from ethylendiamine and oleic acid) These d sadva es can be obviated by the and 15 parts of solvent naphtha are mixed topresent invention by means of which the desired gather nd th parts of ethanol and 10 parts result can be obtained in asimpler and univerf w t r are dded, Sally reliable manner and for this purpose the In this way the addition of 1.5% of a nitroinve t on Co s in a Process for preventing genous soap completely prevents the deposition the deposition of dispersed substances in dis- M of the dispersed pigment. persions, for example in non-aqueous paints and In the above example the oleic acid may be replaced by stearic acid and the base may be replaced by an amine containing hydroxyl groups which produces-a .further advantage in that the undesired floating of the colouring material is completely prevented.

The added substances may be introduced-before the introduction of the pigment and the blending agent but it is to be emphasized that a particular advantage of the invention is to enable the dispersion to be facilitated at a later stage if desired or necessary.

The addition of water previously mentioned sometimes makes necessary the addition of an intermediary solvent for the water and the binding agent. In the above example ethanol is used for this purpose.

Instead of ethanol other water-soluble alcohols may of course be used, as well as acetone, lactic acid, methyl or ethyl glycolate, or glycol or the water-soluble ether or ester thereof.

The process according to the invention is also applicable to other kinds of dispersions for preventing the formation of hard deposits.

Having now particularly described and ascertained the nature of my invention and in what manner the same is to be performed, I declare that what 1 claim is:

1. A paint comprising a water insoluble paint vehicle, pigment dispersed therein, a small amount of water soluble amine soap, and a small amount of water not less than that produced in reacting an amine and a fatty acid in forming said soap, the soap and water serving to prevent 'the pigment. from settling out as a hard sediment.

the water being not less than that produced in reacting an amine with a fatty acid in forming said soap, and working the mass until the pigment is redispersed into the vehicle.

PAUL KtimmL. 

